| Horizon City to Oberkirch | 5,574.74 mi (8,971.68 km) |
| Horizon City to Obernburg am Main | 5,556.01 mi (8,941.54 km) |
| Horizon City to Obernkirchen | 5,450.72 mi (8,772.09 km) |
| Horizon City to Oberschleissheim | 5,710.67 mi (9,190.44 km) |
| Horizon City to Oberstdorf | 5,702.53 mi (9,177.33 km) |
| Horizon City to Obertraubling | 5,699.14 mi (9,171.89 km) |
| Horizon City to Obertshausen | 5,535.54 mi (8,908.59 km) |
| Horizon City to Oberursel | 5,520.78 mi (8,884.83 km) |
| Horizon City to Ochsenfurt | 5,596.36 mi (9,006.47 km) |
| Horizon City to Ochsenhausen | 5,661.48 mi (9,111.26 km) |
| Horizon City to Ochtrup | 5,388.75 mi (8,672.35 km) |
| Horizon City to Odenthal | 5,435.06 mi (8,746.88 km) |
| Horizon City to Oelde | 5,436.79 mi (8,749.66 km) |
| Horizon City to Oelsnitz | 5,633.55 mi (9,066.32 km) |
| Horizon City to Oer-Erkenschwick | 5,414.27 mi (8,713.42 km) |
